Trail #18A's Logical Extension
Though predating the Incinerator Ridge Trail #18A, when taken with that trail, Trail #45 seems like it was built to complete trail #18A. The sign for the trailhead is at the end of the Incinerator Ridge Road, and it can easily be hiked as an out and back from that point to Mount Bigelow, and with no other trails included. This write up is for that purpose.
The current trailhead sign is the metal post at the start of trail #18A, though the arrow for this trail points back towards the parking area. There is no other sign for this trail at the trailhead, at this writing, that I could locate. It takes a slight amount of effort to locate the trail, and you will have to pass through a camping area which might have some folks camped in it, but once on the trail it is impossible to accidentally leave it. From the parking area, hike uphill towards Mount Bigelow, on the ridge between the cliff on the right and the road on the left, this will take you to the trail. You'll be 100% sure when you are on the trail.
Trail #45 hikes up through shrub oaks and a series of switchbacks, going around what must be Kellogg Mountain, but not over it. It stays on the western side of the ridge for most of it's journey. Just past an area of grass and pines, it can be said to either intersect or end at the Mount Bigelow Trail, or what should be that trail. It probably ends at this point, or does officially, but being so close the stats take you to the Mount Bigelow Road. A USFS sign at the junction is titled for the, "Butterfly Trail", and neither makes any references to trail #45, nor does the sign have any arrows for the trail going to the Incinerator Ridge Road, indicating it was probably built after this sign was installed. Signs in this area of the Coronado NF can be confusing. From Mount Bigelow, you can hike back the way you came, or use other trails to create a longer loop.
Check out the Official Route and Triplogs.
This hike is listed as One-Way.
When hiking several trails on a single "hike", log it with a generic name that describes the hike. Then link the trails traveled, check out the example.